\\[-1.8ex] Soil Heterogeneity & $-$0.090$^{***}$ & $-$0.083$^{***}$ & $-$0.089$^{**}$ & $-$0.086$^{*}$ \\ 
  & (0.022) & (0.022) & (0.044) & (0.044) \\ 
\\[-1.8ex] 
Observations & 7,495 & 7,495 & 2,038 & 2,038 \\ 
R$^{2}$ & 0.237 & 0.252 & 0.471 & 0.473 \\ 
